Application of Renormalization Group Techniques to a Homogeneous Bose Gas at Finite Temperature
Abstract
A homogeneous Bose gas is investigated at finite temperature using renormalization group techniques. A non--perturbative flow equation for the effective potential is derived using sharp and smooth cutoff functions. Numerical solutions of these equations show that the system undergoes a second order phase transition in accordance with universality arguments. We obtain the critical exponent
ν=0.73
to leading order in the derivative expansion.